In the LIO's circuit, you can expect thousands of hours on the tubes (5+ years is not out of the ordinary here!)

Vinnie

Would this be around 2,3 thousands of 8,9 thousands?I am asking as LIO is being used for TV watching as well, so one can easily hit 10 hours daily. What will I notice first when the tubes start to deteriorate?

Would this be around 2,3 thousands of 8,9 thousands?I am asking as LIO is being used for TV watching as well, so one can easily hit 10 hours daily.

Hi mirekti,

I don't have a way of knowing for sure, and I do have some customers still using their stock 6922 tubes from theirRed Wine Audio Signature 15 from year 2010, and they still seem to perform like new.

I expect this same type of longevity with the tubes used in LIO's circuitry (with the 6922s, and DHTs).

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What will I notice first when the tubes start to deteriorate?

You would probably notice lower output level (reduced gain), noise, and perhaps more drastic signs (pops, intermittent sound, etc.).Most likely, it would be in one channel, as the chances of both tubes showing this at the same time is unlikely. So then you can swaptubes and see if it follows the tube or not.

Again - I don't think you'll hear this for 5 - 10 thousands of hours or more...

Well, I think most were initially developed to push out sound as repeaters in telephone use (no, not the 300B, but the 101D for sure). I find tube design, etc. fascinating and have gone full on down the rabbit hole on some of this stuff. My wife believes me to be insane... I am reading a book about pre-1940 tube design in England currently. Anyway, I have always wondered whether there is truth to the statement that putting less voltage on the plates will provide longer life. The reason I wonder is because the cathode (heated by the filament or the filament in a DHT) is hot the entire time and releasing electrons. If the electron cloud is formed, does the electron remain bonded to the atom in the filament or is the bond broken such that it does not rebond to the cathode. I would assume the latter, not the former.

Regardless, I always think the 7dJ8 will last longer than the 6dj8 if you are running at 6.3v because you are hearing the filament a bit less than its rating.